Like this video? Subscribe to our free daily email and get a new idiom video every day!
a head-scratcher
A thoroughly complex or difficult mystery, problem, puzzle, or riddle. I'm not sure how we'll be able to reach an agreement with the labor unions on this issue. It's a head-scratcher, to be sure.A: "What is weightless but can be seen, and if you put it in a bucket, it will make the bucket lighter?" B: "Hmm, I don't know. That's a real head-scratcher!"